In what may be the first true western showdown, Wild Bill Hickok shoots Dave Tutt dead in the market square of Springfield, Missouri.

Hollywood movies and dime novels notwithstanding, the classic western showdown—also called a walkdown—happened only rarely in the American West. Rather than coolly confronting each other on a dusty street in a deadly game of quick draw, most men began shooting at each other in drunken brawls or spontaneous arguments. Ambushes and cowardly attacks were far more common than noble showdowns.

Nonetheless, southern emigrants brought to the West a crude form of the “code duello,” a highly formalized means of solving disputes between gentlemen with swords or guns that had its origins in European chivalry. By the second half of the 19th century, few Americans still fought duels to solve their problems. Yet, the concept of the duel surely influenced the informal western code of what constituted a legitimate-and legal-gun battle. Above all, the western code required that a man resort to his six-gun only in defense of his honor or life, and only if his opponent was also armed. Likewise, a western jury was unlikely to convict a man in a shooting provided witnesses testified that his opponent had been the aggressor.

The best-known example of a true western duel occurred on this day in 1865. Wild Bill Hickok, a skilled gunman with a formidable reputation, was eking out a living as a professional gambler in Springfield, Missouri. He quarreled with Dave Tutt, a former Confederate soldier, but it is unclear what caused the dispute. Some people say it was over a card game while others say they fought over a woman. Whatever the cause, the two men agreed to a duel.

The showdown took place the following day with crowd of onlookers watching as Hickok and Tutt confronted each other from opposite sides of the town square. When Tutt was about 75 yards away, Hickok shouted, “Don’t come any closer, Dave.” Tutt nervously drew his revolver and fired a shot that went wild. Hickok, by contrast, remained cool. He steadied his own revolver in his left hand and shot Tutt dead with a bullet through the chest.

Having adhered to the code of the West, Hickok was acquitted of manslaughter charges. Eleven years later, however, Hickok died in a fashion far more typical of the violence of the day: a young gunslinger shot him in the back of the head while he played cards. Legend says that the hand Hickok was holding at the time of his death was two pair–black aces and black eights. The hand would forever be known as the “dead man’s hand.”